Heat Shield Assembly and Method

ABSTRACT

A heat shield assembly including a skin panel and a stiffener including a base portion and a bead portion protruding from the base portion, wherein the base portion is connected to the skin panel to define a bead volume between the bead portion and the skin panel.

FIELD

This application relates to heat shields, such as heat shields onaircraft, and, more particularly, to stiffening of heat shields.

BACKGROUND

An externally mounted aircraft engine is typically attached to theassociated aircraft by a pylon. As one example, the pylon may couple theengine to a wing of the aircraft (e.g., the engine may be suspendedbelow the wing by way of the pylon). As another example, the pylon maycouple the engine directly to the fuselage of the aircraft (e.g., thepylon may extend between the engine and the side of the fuselageproximate the rear of the fuselage). For aerodynamic purposes, the pylonis typically housed within a fairing.

Due to proximity with the aircraft engine, particularly with the hotexhaust gases emanating from the aircraft engine, a pylon fairingtypically includes a heat shield. For example, the aft pylon fairing ona commercial aircraft can include a heat shield as a subcomponentthereof. A typical heat shield includes skin panels attached to framemembers to define an internal volume/compartments. The internalvolume/compartments of the heat shield may be filled with a thermalinsulation material.

The skin panels of a heat shield are formed from various heat-resistantmaterials, such as aerospace-grade titanium alloys. Nonetheless, theskin panels of a heat shield may be susceptible to buckling when heated,particular on larger aircraft where the distance between adjacent framemembers is greater.

Accordingly, those skilled in the art continue with research anddevelopment efforts in the field of aircraft heat shields.

SUMMARY

In one embodiment, the disclosed heat shield assembly may include a skinpanel and a stiffener including a base portion and a bead portionprotruding from the base portion, wherein the base portion is connectedto the skin panel to define a bead volume between the bead portion andthe skin panel.

In one embodiment, the disclosed method for stiffening a skin panel of aheat shield assembly may include the steps of (1) forming a blank into astiffener including a base portion and a bead portion protruding fromthe base portion and (2) connecting the base portion to the skin panel.

Other embodiments of the disclosed heat shield assembly and method willbecome apparent from the following detailed description, theaccompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of an aircraft incorporating thedisclosed heat shield assembly;

FIG. 2 is a side elevational view of a portion of the aircraft of FIG.1, showing a pylon fairing disposed between a wing and an engine;

FIG. 3 is a rear perspective view of a portion of the pylon fairing ofFIG. 2;

FIG. 4 is a side perspective view of a heat shield assembly of the pylonfairing of FIG. 3, shown with a side skin panel removed to exposeunderlying structure;

FIG. 5A is a perspective view of the stiffener of the heat shieldassembly of FIG. 4;

FIG. 5B is a top plan view of the stiffener of FIG. 5A;

FIG. 5C is a cross-sectional view of the stiffener of FIG. 5B;

FIG. 6A is a cross-sectional view of a portion of the heat shieldassembly of FIG. 4;

FIG. 6B depicts one variation to the portion of the heat shield assemblyshown in FIG. 6A;

FIGS. 7A and 7B depict one example method for manufacturing a stiffenerfor a heat shield assembly in accordance with the present disclosure;

FIG. 8 is a perspective view of a portion of the heat shield assembly ofFIG. 4 in accordance with one embodiment of the present disclosure;

FIG. 9 is a perspective view of a portion of a heat shield assembly inaccordance with a first alternative embodiment;

FIG. 10 is a perspective view of a portion of a heat shield assembly inaccordance with a second alternative embodiment;

FIG. 11 is a perspective view of a portion of a heat shield assembly inaccordance with a third alternative embodiment;

FIG. 12 is a perspective view of a portion of a heat shield assembly inaccordance with a fourth alternative embodiment;

FIG. 13 is a perspective view of a portion of a heat shield assembly inaccordance with a fifth alternative embodiment;

FIG. 14 is a flow diagram of an aircraft manufacturing and servicemethodology; and

FIG. 15 is a block diagram of an aircraft.

DETAILED DESCRIPTION

The disclosed heat shield assembly 100 may be incorporated into anaircraft, such as a fixed-wing aircraft 10, as shown in FIG. 1, or arotary-wing aircraft. Various aircraft, including commercial aircraft,personal aircraft and military aircraft, may benefit from the disclosedheat shield assembly 100 without departing from the scope of the presentdisclosure.

Referring to FIGS. 1 and 2, in one particular aspect, the disclosedaircraft 10 may include a fuselage 12, one or more wings 14 (two wings14 are shown in FIG. 1) and one or more engines 16 (two engines 16 areshown in FIG. 1). Each wing 14 of the aircraft 10 may be fixedlyconnected to, and may outwardly extend from, the fuselage 12. Eachengine 16 may be connected to (e.g., suspended below) an associated wing14 by way of a pylon 18, which is shown schematically in FIG. 1 as abroken line. The pylon 18 (a structural member) may be enclosed within apylon fairing 20 (an aerodynamic member). The disclosed heat shieldassembly 100 may be associated with (e.g., connected to/integral with)the pylon fairing 20, which may be (or may include) an aft pylonfairing.

As shown in FIG. 2, each engine 16 of the aircraft 10 may be a jetengine, such as a high bypass ratio turbofan engine, and includes aninlet side 22 and an outlet side 24 longitudinally opposed from theinlet side 22. Therefore, each engine 16 of the aircraft 10 outputs anexhaust jet 26 that propels the aircraft 10 in the forward direction(arrow F). The disclosed heat shield assembly 100 may be positionedproximate the outlet side 24 of the engine 16, such as proximate anexhaust nozzle 28, such that the heat shield assembly 100 is disposedbetween the exhaust jet 26 and the bulk 30 of the pylon fairing 20.

Referring to FIGS. 3 and 4, the disclosed heat shield assembly 100includes one or more skin panels 102 and one or more stiffeners 112. Theheat shield assembly 100 may further include one or more frame members110. In the illustrated embodiment, the heat shield assembly 100 mayspecifically include as the skin panels 102 a base skin panel 104 andtwo side skin panels 106 (FIG. 3), 108 (FIG. 4). The base skin panel 104and the side skin panels 106, 108 may be placed over and connected tothe frame members 110 to define a three-dimensional body 114 having aninternal volume 116 (FIG. 4). Connection between the skin panels 102 andthe frame members 110 may be effected using various techniques, such asby welding and/or with mechanical fasteners (e.g., rivets, nuts/bolts,etc.).

A thermal insulation material 118 (FIG. 4) may optionally be positionedin the internal volume 116 of the body 114 of the heat shield assembly100. Various compositions (e.g., ceramics, fiberglass, etc.) may be usedas the thermal insulation material 118, and the thermal insulationmaterial 118 may be provided in various physical forms (e.g., foams,monoliths, bulk material, sheets, blankets, etc.), without departingfrom the scope of the present disclosure. As one specific, non-limitingexample, the thermal insulation material 118 may be (or may include)aluminum oxide fibers, such as SAFFIL® aluminum oxide fiberscommercially available from Saffil Ltd. of Cheshire, United Kingdom

The frame members 110 may be spaced along a primary longitudinal axis X(FIG. 4) of the heat shield assembly 100, which may be generallyparallel with the centerline C (FIG. 2) of the associated engine 16(FIG. 2). Therefore, the frame members 110 may divide the internalvolume 116 of the body 114 into a plurality of compartments 120 (eightdistinct compartments 120 are shown in FIG. 4). One or more compartments120 (e.g., each compartment 120) may contain thermal insulation material118, even though four compartments 120 are shown in FIG. 4 containingthermal insulation material 118.

A cover 122 (FIG. 4) may optionally be positioned over the body 114 ofthe heat shield assembly 100 to enclose the internal volume 116. Thecover 122 may be connected to the skin panels 102 and/or the framemembers 110 using various techniques, such as by welding and/or withmechanical fasteners (e.g., rivets, nuts/bolts, etc.). Functionally, thecover 122 of the heat shield assembly 100 may contain the thermalinsulation material 118 within the internal volume 116 of the body 114,while inhibiting the unintended introduction of foreign matter (e.g.,oil, grease, dirt, debris, etc.) into the internal volume 116 of thebody 114.

Because of the proximity to the exhaust jet 26 (FIG. 2) and the hightemperature associated therewith, the base skin panel 104, the side skinpanels 106, 108 and/or the frame members 110 of the disclosed heatshield assembly 100 may be formed from a material (or combination ofmaterials) that is tolerant to relatively high temperatures. In oneexpression, the base skin panel 104, the side skin panels 106, 108and/or the frame members 110 may be formed from a metallic material,such as a titanium alloy. As one specific, non-limiting example, thebase skin panel 104, the side skin panels 106, 108 and the frame members110 may be formed from Ti-6242 (Ti-6Al-2Sn-4Zr-2Mo) or a similartitanium alloy. In another expression, the base skin panel 104, the sideskin panels 106, 108 and/or the frame members 110 may be formed from acomposite material, such as a ceramic composite.

As shown in FIG. 4, the stiffener 112 may be separate from, butconnected to, one or more of the skin panels 102 (shown connected to thebase skin panel 104) to provide structural reinforcement to the skinpanel 102 and, thus, serves a stiffening function. Therefore, when theheat shield assembly 100 is heated to a relatively high temperature,such as due to exposure to the exhaust jet 26 of engine 16, as shown inFIG. 2, the stiffened skin panel 102 may be less likely to buckle.

Referring to FIGS. 5A-5C, the stiffener 112 of the heat shield assembly100 may include a monolithic body 130 that defines a base portion 132and at least one bead portion 134 (three bead portions 134 are shown inFIGS. 5A and 5B). Each bead portion 134 protrudes outward a distance D(FIG. 5C) from the base portion 132 to define a bead volume 136 (FIG.5C) between the bead portion 134 and the subjacent base portion 132. Afillet 138 may extend about the bead portion 134 to provide a smoothtransition from the bead portion 134 to the surrounding base portion132.

The protruding distance D (FIG. 5C) of the bead portion 134 of thestiffener 112 may be dictated by the size of the bead portion 134, suchas the width W (FIG. 5C) of the bead portion 134 (transverse to thelongitudinal axis A (FIG. 5B) of the bead portion 134). To provide thestiffener 112 with a low profile, the protruding distance D of the beadportion 134 may be less than or equal to the width W of the bead portion134. In one expression, the protruding distance D of the bead portion134 may range from about 5 percent to about 95 percent of the width W ofthe bead portion 134. In another expression, the protruding distance Dof the bead portion 134 may range from about 10 percent to about 80percent of the width W of the bead portion 134. In yet anotherexpression, the protruding distance D of the bead portion 134 may rangefrom about 20 percent to about 50 percent of the width W of the beadportion 134.

As best shown in FIG. 5C, in one particular construction, the beadportion 134 may have a generally continuous curvature. For example, thebead portion 134 may have a semi-circular profile in cross-section (FIG.5C), as dictated by a radius R of the bead portion 134. The radius R ofthe bead portion 134 can be selected based on the cross-sectionalthickness T of the stiffener 112 and the overall size of the stiffener112, among other possible factors. Other cross-sectional profiles of thebead portion 134, such as arcuate or semi-elliptical, are alsocontemplated.

Referring to FIG. 5B, each bead portion 134 may be elongated along alongitudinal axis A. In the illustrated embodiment, each of the threebead portions 134 may be coaxially aligned, but spaced apart, along asingle longitudinal axis A. However, non-aligned configurations arecontemplated and described herein. Therefore, each bead portion 134 hasa length L. The length L of the bead portion 134 can be selected basedon the radius R (FIG. 5C) of the bead portion 134 and the overall sizeof the stiffener 112, among other possible factors.

The length L (FIG. 5B) of the bead portion 134 may be expressed as afunction of the width W (FIG. 5C) of the bead portion 134, and viceversa. In one expression, the length L of the bead portion 134 may be atleast 5 times the width W of the bead portion 134. In anotherexpression, the length L of the bead portion 134 may be at least 10times the width W of the bead portion 134. In another expression, thelength L of the bead portion 134 may be at least 50 times the width W ofthe bead portion 134. In yet another expression, the length L of thebead portion 134 may be at least 100 times the width W of the beadportion 134.

As best shown in FIG. 5B, each bead portion 134 may be elongated alongthe longitudinal axis A from a first end portion 140 to a second endportion 142. The first and second end portions 140, 142 of the beadportion 134 may be hemispherical in plan view, thereby eliminatingcorners and providing a smooth and continuous transition from the beadportion 134 to the base portion 132.

The stiffener 112 of the disclosed heat shield assembly 100 may beformed from a material (or combination of materials) tolerant torelatively high temperatures. The material used to form the stiffener112 may be the same as, similar or different from the material used toform one or more of the base skin panel 104, the side skin panels 106,108 and the frame members 110. In one expression, the stiffener 112 maybe formed from a metallic material, such as a titanium alloy. As onespecific, non-limiting example, the stiffener 112 may be formed fromTi-6242 (Ti-6Al-2Sn-4Zr-2Mo) or a similar titanium alloy. In anotherexpression, the stiffener 112 may be formed from a composite material,such as a ceramic composite.

As shown in FIGS. 4 and 6, the stiffener 112 is connected to a skinpanel 102 of the heat shield assembly 100, such as to the base skinpanel 104 of the heat shield assembly 100. The base skin panel 104includes an exterior surface 146 (FIGS. 3 and 6) and an interior surface148 (FIGS. 4 and 6). The stiffener 112 may be connected to the interiorsurface 148 of the base skin panel 104.

Connection between the stiffener 112 and the interior surface 148 of thebase skin panel 104 may be made by way of the base portion 132 of thebody 130 of the stiffener 112. Specifically, the base portion 132 of thestiffener 112 may act as a flange that facilitates connecting thestiffener 112 to the base skin panel 104. Therefore, when the baseportion 132 is properly connected to the base skin panel 104, the beadportion 134 of the body 130 of the stiffener 112 protrudes outward fromthe base skin panel 104 and the base skin panel 104 encloses, at leastpartially, the bead volume 136.

Various techniques may be used to effect a connection between the baseportion 132 of the stiffener 112 and the base skin panel 104. As onenon-limiting example, the base portion 132 of the stiffener 112 may beconnected to the base skin panel 104 by thermal joints 133, such as bywelding, brazing or soldering, as shown in FIG. 6A. As anothernon-limiting example, mechanical fasteners, such as rivets, nuts/bolts,screws and the like, may be used to connect the base portion 132 of thestiffener 112 to the base skin panel 104, as shown in FIG. 6B.

Without being limited to any particular theory, it is believed thatconnecting a stiffener 112 having a bead portion 134 directly to a skinpanel 102 of a heat shield assembly 100, particularly to the base skinpanel 104 of a heat shield assembly 100, may advantageously stiffen theskin panel 102, thereby may reduce (if not eliminate) the occurrence ofbuckling when the heat shield assembly 100 is heated, such as by theexhaust jet 26 of an engine 16, as shown in FIG. 2. Significantly, thelow profile of the bead portion 134 of the disclosed stiffener 112 mayfacilitate introducing the stiffener 112 to a heat shield assembly 100with little or no modification to the other components (e.g., the framemembers 110 and the thermal insulation material 118) of the heat shieldassembly 100. Therefore, the disclosed stiffener 112 may be connected tothe skin panel 102 of a heat shield assembly 100 as an originalcomponent or, alternatively, the heat shield assembly 100 may beretrofitted to include the stiffener 112.

Various techniques may be employed for forming the disclosed stiffener112 depending on various considerations, including cost and thecomposition of the material being formed into the disclosed stiffener112.

In one particular implementation, the disclosed stiffener 112 may beformed using a superplastic forming process. However, other suitablemethods may be used to form the stiffener 112. As shown in FIG. 7A, ablank 150 of material is positioned on a die 152. The blank 150 may beformed from a metal or metal alloy, such as a titanium alloy (e.g.,Ti-6242), though use of non-metallic materials is also contemplated.Prior to placement of the blank 150 on the die 152, the blank 150 is cut(e.g., die-cut) to the desired silhouette (e.g., an elongatedrectangular strip). A cover 154 is positioned over the blank 150,thereby sandwiching the blank 150 between the die 152 and the cover 154.

To effect the desired superplastic formation, the blank 150 (as well asthe die 152 and the cover 154) is heated to a temperature at which thematerial of the blank 150 becomes superplastic. For example, when theblank 150 is formed from a titanium alloy, superplasticity of the blank150 may be achieved by heating the blank 150 to a temperature rangingfrom about 1,450° F. to about 1,850° F. Once at the desired temperature,the blank 150 is formed against the die 152, such as by injecting a gas156 (e.g., an inert gas/gas mixture) between the blank 150 and the cover154 to urge the superplastic blank 150 against the die 152, as shown inFIG. 7B. In one variation, rather than injecting a gas 156, a vacuum maybe drawn through the die 152 to urge the superplastic blank 150 againstthe die 152. In another variation, rather than injecting a gas 156 ordrawing a vacuum, the superplastic blank 150 may be shaped against thedie 152 under the force of gravity.

Referring to FIGS. 4 and 8, in one particular embodiment, the disclosedstiffener 112 may be connected to the base skin panel 104 such that thebead portions 134 of the stiffener 112 are oriented in substantialalignment with the primary longitudinal axis X (FIG. 4) of the heatshield assembly 100 (e.g., the longitudinal axis A (FIG. 5A) of the beadportions 134 of the stiffener 112 may be parallel with the primarylongitudinal axis X of the heat shield assembly 100). Furthermore, sinceonly one stiffener 112 is shown in FIGS. 4 and 8, the stiffener 112 maybe generally centered relative to the base skin panel 104. However,variations in the location of the stiffener 112 vis-à-vis the base skinpanel 104, as well as variations in the orientation of the stiffener 112vis-à-vis the primary longitudinal axis X of the heat shield assembly100, will not result in a departure from the scope of the presentdisclosure.

Referring to FIG. 9, in one alternative embodiment, plural stiffeners112′ are connected to the base skin panel 104′ of the disclosed heatshield assembly 100′. Each stiffener 112′ (or some stiffeners 112′) maybe separate from, and not directly connected to, the other stiffeners112′. While eight stiffeners 112′ are specifically shown in FIG. 9, fewthan eight stiffeners 112′ (e.g., only one stiffener 112′) or more thaneight stiffeners 112′ may be included without departing from the scopeof the present disclosure. The number of stiffeners 112′ included in aheat shield assembly 100′ can be selected based on, among other possiblefactors, the overall size of each stiffener 112′ and the overall size ofthe base skin panel 104′.

Still referring to FIG. 9, the stiffeners 112′ of the heat shieldassembly 100′ may be connected to the base skin panel 104′ such that thebead portion 134′ of each stiffener 112′ (or of some stiffeners 112′) istransverse (e.g., lateral) with respect to the primary longitudinal axisX (FIG. 4) of the heat shield assembly 100′. Various alternativeorientations (e.g., not aligned and not lateral) vis-à-vis the primarylongitudinal axis X of the heat shield assembly 100′ may be used withoutresulting in a departure from the scope of the present disclosure.

Referring to FIG. 10, in another alternative embodiment, pluralstiffeners 212 are connected to the base skin panel 204 of the disclosedheat shield assembly 200, though using only one stiffener 212 is alsocontemplated. Each stiffener 212 is substantially similar to stiffeners112 and 112′, except for the shape of the bead portion 234. Morespecifically, each stiffener 212 (or some stiffeners 212) includes abead portion 234 that is elongated, but not linear (like stiffeners 112and 112′). In the specific embodiment illustrated in FIG. 10, the beadportion 234 may form a chevron pattern on the stiffener 212. The baseportion 232 surrounding the bead portion 234 may closely correspond tothe bead portion 234, thereby giving the stiffener 212 a chevron profilein plan view.

Referring to FIG. 11, in another alternative embodiment, pluralstiffeners 212′ are connected to the base skin panel 204′ of thedisclosed heat shield assembly 200′, though using only one stiffener212′ is also contemplated. Stiffeners 212′ are substantially similar tostiffeners 112 and 112′, except for the shape of the bead portions 234′,235′. More specifically, each stiffener 212′ (or some stiffeners 212′)includes a first bead portion 234′ and a second bead portion 235′, andthe second bead portion 235′ intersects the first bead portion 234′ atan intermediate area between the ends of the bead portions 234′, 235′.Therefore, the bead portions 234′, 235′ may form a cruciform (e.g. X) onthe stiffener 212′. The base portion 232′ surrounding the bead portion234′ may closely correspond to the bead portions 234′, 235′, therebygiving the stiffener 212′ an X-shape in plan view.

Referring to FIG. 12, in another alternative embodiment, pluralstiffeners 312 are connected to the base skin panel 304 of the disclosedheat shield assembly 300, though using only one stiffener 312 is alsocontemplated. Stiffeners 312 are substantially similar to stiffeners 112and 112′, except for the shape of the bead portions 334. Morespecifically, each stiffener 312 (or some stiffeners 312) includesplural bead portions 334 protruding from the base portion 332. Each beadportion 334 of a stiffener 312 may be separate from and generallyparallel with the other bead portions 334 of the stiffener 312 (notintersecting), and the bead portions 334 may be laterally oriented withrespect to the primary longitudinal axis X (FIG. 4) of the heat shieldassembly 300. Various alternative (e.g., non-lateral) orientationsvis-a-vis the primary longitudinal axis X of the heat shield assembly300 may be used without resulting in a departure from the scope of thepresent disclosure.

Referring to FIG. 13, in yet another alternative embodiment, pluralstiffeners 312′ are connected to the base skin panel 304′ of thedisclosed heat shield assembly 300′, though using only one stiffener312′ is also contemplated. Stiffeners 312′ are substantially similar tostiffeners 112 and 112′, except for the shape of the bead portions 334′.More specifically, each stiffener 312′ (or some stiffeners 312′)includes plural bead portions 334′ protruding from the base portion332′. Each bead portion 334′ of a stiffener 312′ may be separate fromthe other bead portions 334′, and may be oriented at an angle T withrespect to the primary longitudinal axis X (FIG. 4) of the heat shieldassembly 300. In one expression, the angle T may range from about 0degrees to about 90 degrees. In another expression, the angle T mayrange from about 0 degrees to about 45 degrees. In another expression,the angle T may range from about 0 degrees to about 30 degrees. Inanother expression, the angle T may range from about 45 degrees to about90 degrees. In yet another expression, the angle T may range from about60 degrees to about 90 degrees.

The location of a stiffener, the number of stiffeners used, the numberof bead portions on a given stiffener, and/or the orientation of thebead portion may be selected to optimize the stiffeners for a particularapplication. Various combinations and variations are possible withoutdeparting from the scope of the present disclosure.

Examples of the disclosure may be described in the context of anaircraft manufacturing and service method 400, as shown in FIG. 14, andan aircraft 402, as shown in FIG. 15. During pre-production, theaircraft manufacturing and service method 400 may include specificationand design 404 of the aircraft 402 and material procurement 406. Duringproduction, component/subassembly manufacturing 408 and systemintegration 410 of the aircraft 402 takes place. Thereafter, theaircraft 402 may go through certification and delivery 412 in order tobe placed in service 414. While in service by a customer, the aircraft402 is scheduled for routine maintenance and service 416, which may alsoinclude modification, reconfiguration, refurbishment and the like.

Each of the processes of method 400 may be performed or carried out by asystem integrator, a third party, and/or an operator (e.g., a customer).For the purposes of this description, a system integrator may includewithout limitation any number of aircraft manufacturers and major-systemsubcontractors; a third party may include without limitation any numberof venders, subcontractors, and suppliers; and an operator may be anairline, leasing company, military entity, service organization, and soon.

As shown in FIG. 15, the aircraft 402 produced by example method 400 mayinclude an airframe 418 with a plurality of systems 420 and an interior422. Examples of the plurality of systems 420 may include one or more ofa propulsion system 424, an electrical system 426, a hydraulic system428, and an environmental system 430. Any number of other systems may beincluded.

The disclosed heat shield assembly and method may be employed during anyone or more of the stages of the aircraft manufacturing and servicemethod 400. As one example, components or subassemblies corresponding tocomponent/subassembly manufacturing 408, system integration 410, and ormaintenance and service 416 may be fabricated or manufactured using thedisclosed heat shield assembly and method. As another example, theairframe 418 may be constructed using the disclosed heat shield assemblyand method. Also, one or more apparatus examples, method examples, or acombination thereof may be utilized during component/subassemblymanufacturing 408 and/or system integration 410, for example, bysubstantially expediting assembly of or reducing the cost of an aircraft402, such as the airframe 418 and/or the interior 422. Similarly, one ormore of system examples, method examples, or a combination thereof maybe utilized while the aircraft 402 is in service, for example andwithout limitation, to maintenance and service 416.

The disclosed heat shield assembly and method are described in thecontext of an aircraft; however, one of ordinary skill in the art willreadily recognize that the disclosed heat shield assembly and method maybe utilized for a variety of applications. For example, the disclosedheat shield assembly and method may be implemented in various types ofvehicle including, e.g., helicopters, passenger ships, automobiles andthe like.

Although various embodiments of the disclosed heat shield assembly andmethod have been shown and described, modifications may occur to thoseskilled in the art upon reading the specification. The presentapplication includes such modifications and is limited only by the scopeof the claims.

What is claimed is:
 1. A heat shield assembly comprising: a skin panel;and a stiffener comprising a base portion and a bead portion protrudingfrom said base portion, wherein said base portion is connected to saidskin panel to define a bead volume between said bead portion and saidskin panel.
 2. The heat shield assembly of claim 1 further comprising aplurality of frame members, wherein said skin panel is connected to saidplurality of frame members.
 3. The heat shield assembly of claim 2wherein said bead portion is positioned between two adjacent framemembers of said plurality of frame members.
 4. The heat shield assemblyof claim 2 wherein said skin panel comprises an interior surface and anexterior surface, said plurality of frame members being connected tosaid interior surface.
 5. The heat shield assembly of claim 4 whereinsaid base portion of said stiffener is connected to said interiorsurface.
 6. The heat shield assembly of claim 2 wherein said skin panelis a base skin panel, and further comprising a first side skin panelconnected to said plurality of frame members and a second side skinpanel connected to said plurality of frame members.
 7. The heat shieldassembly of claim 1 wherein said stiffener comprises a monolithic body,and wherein said monolithic body defines said base portion and said beadportion.
 8. The heat shield assembly of claim 1 wherein said stiffenercomprises a fillet between said base portion and said bead portion. 9.The heat shield assembly of claim 1 wherein said base portion isconnected to said skin panel by a thermal joint.
 10. The heat shieldassembly of claim 1 wherein said base portion is connected to said skinpanel by a mechanical fastener.
 11. The heat shield assembly of claim 1wherein said bead portion comprises a continuous curvature.
 12. The heatshield assembly of claim 1 defining a primary longitudinal axis, whereinsaid bead portion is elongated along a longitudinal axis.
 13. The heatshield assembly of claim 12 wherein said longitudinal axis of said beadportion is substantially aligned with said primary longitudinal axis.14. The heat shield assembly of claim 12 wherein said longitudinal axisof said bead portion is transverse with respect to said primarylongitudinal axis.
 15. The heat shield assembly of claim 1 wherein saidstiffener further comprises a second bead portion.
 16. The heat shieldassembly of claim 15 wherein said second bead portion intersects saidbead portion.
 17. An aircraft comprising a pylon fairing, wherein saidpylon fairing comprises said heat shield assembly of claim
 1. 18. Amethod for stiffening a skin panel of a heat shield assembly, saidmethod comprising: forming a blank into a stiffener comprising a baseportion and a bead portion protruding from said base portion; andconnecting said base portion to said skin panel.
 19. The method of claim18 wherein said forming step comprises: heating said blank to atemperature at which said blank is superplastic; and shaping saidsuperplastic blank against a die.
 20. The method of claim 19 whereinsaid shaping step comprising injecting a gas to urge said superplasticblank against said die.